Typically, a prismatic interior rearview mirror assembly includes a mirror reflective element that is attached to an attachment plate and at least partially received in a casing, with a bezel portion snapped to the casing so that the bezel portion and casing overlap or encompass a perimeter edge of the reflective element and a portion or perimeter region of an outer or front surface of the reflective element (the surface facing the driver of the vehicle when the mirror assembly is normally mounted in the vehicle). The reflective element is adjustable by the driver to adjust the rearward field of view provided by the mirror reflective element.